[PATCH 1/1] staging: rtl8192e: Rework EEPROM handling code
Mateusz Kulikowski
mateusz.kulikowski at gmail.com
Thu Jul 30 21:48:50 UTC 2015
Card configuration is stored in SPI EEPROM (93c46 or 93c56)
working in 128|256x16 mode.
Communication is handled using GPIO bitbang.
>From behaviour perspective, delay after read was removed.
It is not needed as we wait after reading GPIO mapped to
PCI-E register - it should have no side effects.
According to sample EEPROM datasheet (AT93Cx6), max frequency for
worst case scenario (1.8V supply) is 250kHZ (vs. 1MHz for 5V).
Driver generates ~50kHZ clock - margin should be big enough
even for devices from other vendors.
Signed-off-by: Mateusz Kulikowski <mateusz.kulikowski at gmail.com>
---
drivers/staging/rtl8192e/rtl8192e/r8192E_hw.h | 8 +-
drivers/staging/rtl8192e/rtl8192e/rtl_eeprom.c | 120 ++++++++-----------------
2 files changed, 43 insertions(+), 85 deletions(-)
diff --git a/drivers/staging/rtl8192e/rtl8192e/r8192E_hw.h b/drivers/staging/rtl8192e/rtl8192e/r8192E_hw.h
index 43c3fb8..c81832d 100644
--- a/drivers/staging/rtl8192e/rtl8192e/r8192E_hw.h
+++ b/drivers/staging/rtl8192e/rtl8192e/r8192E_hw.h
@@ -119,10 +119,10 @@ enum _RTL8192Pci_HW {
#define EPROM_CMD_NORMAL 0
#define EPROM_CMD_LOAD 1
#define EPROM_CMD_PROGRAM 2
-#define EPROM_CS_SHIFT 3
-#define EPROM_CK_SHIFT 2
-#define EPROM_W_SHIFT 1
-#define EPROM_R_SHIFT 0
+#define EPROM_CS_BIT 3
+#define EPROM_CK_BIT 2
+#define EPROM_W_BIT 1
+#define EPROM_R_BIT 0
AFR = 0x010,
#define AFR_CardBEn (1<<0)
diff --git a/drivers/staging/rtl8192e/rtl8192e/rtl_eeprom.c b/drivers/staging/rtl8192e/rtl8192e/rtl_eeprom.c
index ed54193..039ccfd 100644
--- a/drivers/staging/rtl8192e/rtl8192e/rtl_eeprom.c
+++ b/drivers/staging/rtl8192e/rtl8192e/rtl_eeprom.c
@@ -25,115 +25,73 @@
#include "rtl_core.h"
#include "rtl_eeprom.h"
-static void eprom_cs(struct net_device *dev, short bit)
+static void _rtl92e_gpio_write_bit(struct net_device *dev, int no, bool val)
{
- if (bit)
- rtl92e_writeb(dev, EPROM_CMD,
- (1 << EPROM_CS_SHIFT) |
- rtl92e_readb(dev, EPROM_CMD));
+ u8 reg = rtl92e_readb(dev, EPROM_CMD);
+
+ if (val)
+ reg |= 1 << no;
else
- rtl92e_writeb(dev, EPROM_CMD,
- rtl92e_readb(dev, EPROM_CMD) &
- ~(1<<EPROM_CS_SHIFT));
+ reg &= ~(1 << no);
+ rtl92e_writeb(dev, EPROM_CMD, reg);
udelay(EPROM_DELAY);
}
-
-static void eprom_ck_cycle(struct net_device *dev)
+static bool _rtl92e_gpio_get_bit(struct net_device *dev, int no)
{
- rtl92e_writeb(dev, EPROM_CMD,
- (1<<EPROM_CK_SHIFT) | rtl92e_readb(dev, EPROM_CMD));
- udelay(EPROM_DELAY);
- rtl92e_writeb(dev, EPROM_CMD,
- rtl92e_readb(dev, EPROM_CMD) & ~(1<<EPROM_CK_SHIFT));
- udelay(EPROM_DELAY);
-}
+ u8 reg = rtl92e_readb(dev, EPROM_CMD);
+ return (reg >> no) & 0x1;
+}
-static void eprom_w(struct net_device *dev, short bit)
+static void _rtl92e_eeprom_ck_cycle(struct net_device *dev)
{
- if (bit)
- rtl92e_writeb(dev, EPROM_CMD, (1<<EPROM_W_SHIFT) |
- rtl92e_readb(dev, EPROM_CMD));
- else
- rtl92e_writeb(dev, EPROM_CMD,
- rtl92e_readb(dev, EPROM_CMD) &
- ~(1<<EPROM_W_SHIFT));
-
- udelay(EPROM_DELAY);
+ _rtl92e_gpio_write_bit(dev, EPROM_CK_BIT, 1);
+ _rtl92e_gpio_write_bit(dev, EPROM_CK_BIT, 0);
}
-
-static short eprom_r(struct net_device *dev)
+static u16 _rtl92e_eeprom_xfer(struct net_device *dev, u16 data, int tx_len)
{
- short bit;
+ u16 ret = 0;
+ int rx_len = 16;
- bit = (rtl92e_readb(dev, EPROM_CMD) & (1<<EPROM_R_SHIFT));
- udelay(EPROM_DELAY);
+ _rtl92e_gpio_write_bit(dev, EPROM_CS_BIT, 1);
+ _rtl92e_eeprom_ck_cycle(dev);
- if (bit)
- return 1;
- return 0;
-}
+ while (tx_len--) {
+ _rtl92e_gpio_write_bit(dev, EPROM_W_BIT,
+ (data >> tx_len) & 0x1);
+ _rtl92e_eeprom_ck_cycle(dev);
+ }
-static void eprom_send_bits_string(struct net_device *dev, short b[], int len)
-{
- int i;
+ _rtl92e_gpio_write_bit(dev, EPROM_W_BIT, 0);
- for (i = 0; i < len; i++) {
- eprom_w(dev, b[i]);
- eprom_ck_cycle(dev);
+ while (rx_len--) {
+ _rtl92e_eeprom_ck_cycle(dev);
+ ret |= _rtl92e_gpio_get_bit(dev, EPROM_R_BIT) << rx_len;
}
+
+ _rtl92e_gpio_write_bit(dev, EPROM_CS_BIT, 0);
+ _rtl92e_eeprom_ck_cycle(dev);
+
+ return ret;
}
u32 rtl92e_eeprom_read(struct net_device *dev, u32 addr)
{
struct r8192_priv *priv = rtllib_priv(dev);
- short read_cmd[] = {1, 1, 0};
- short addr_str[8];
- int i;
- int addr_len;
- u32 ret;
+ u32 ret = 0;
- ret = 0;
rtl92e_writeb(dev, EPROM_CMD,
(EPROM_CMD_PROGRAM << EPROM_CMD_OPERATING_MODE_SHIFT));
udelay(EPROM_DELAY);
- if (priv->epromtype == EEPROM_93C56) {
- addr_str[7] = addr & 1;
- addr_str[6] = addr & (1<<1);
- addr_str[5] = addr & (1<<2);
- addr_str[4] = addr & (1<<3);
- addr_str[3] = addr & (1<<4);
- addr_str[2] = addr & (1<<5);
- addr_str[1] = addr & (1<<6);
- addr_str[0] = addr & (1<<7);
- addr_len = 8;
- } else {
- addr_str[5] = addr & 1;
- addr_str[4] = addr & (1<<1);
- addr_str[3] = addr & (1<<2);
- addr_str[2] = addr & (1<<3);
- addr_str[1] = addr & (1<<4);
- addr_str[0] = addr & (1<<5);
- addr_len = 6;
- }
- eprom_cs(dev, 1);
- eprom_ck_cycle(dev);
- eprom_send_bits_string(dev, read_cmd, 3);
- eprom_send_bits_string(dev, addr_str, addr_len);
-
- eprom_w(dev, 0);
-
- for (i = 0; i < 16; i++) {
- eprom_ck_cycle(dev);
- ret |= (eprom_r(dev)<<(15-i));
- }
-
- eprom_cs(dev, 0);
- eprom_ck_cycle(dev);
+ /* EEPROM is configured as x16 */
+ if (priv->epromtype == EEPROM_93C56)
+ ret = _rtl92e_eeprom_xfer(dev, (addr & 0xFF) | (0x6 << 8), 11);
+ else
+ ret = _rtl92e_eeprom_xfer(dev, (addr & 0x3F) | (0x6 << 6), 9);
rtl92e_writeb(dev, EPROM_CMD,
(EPROM_CMD_NORMAL<<EPROM_CMD_OPERATING_MODE_SHIFT));
--
1.8.4.1
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